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By A Scott, I Onederra

A great deal of technical and research effort has been applied to the development of models to predict fragmentation from rock blasting. A number of quite useful empirical or engineering models are currently available to blasting engineers and consultants, while more sophisticated approaches using mechanistic and numerical descriptions of rock breakage continue to be developed and applied by researchers and explosives companies.The fragmentation resulting from any blast will be heavily dependent on the properties of the rock mass being blasted; however, most empirical models rely on ‘rock factors’ generated from simple rock mass properties to describe the influence of the rock on the blasting outcome. In contrast, mechanistic models need explicit rock mass properties that require sophisticated laboratory measurements and detailed structural data if realistic outcomes are to be generated. The fragmentation modeller is caught between excessively simple rock mass descriptions for the empirical models and excessively complex data requirements for the mechanistic models.This paper briefly reviews the basis of a range of fragmentation models and the rock mass properties on which they rely. Shortcomings in the way that the mining industry tends to characterise the blasting properties of rock are discussed and some practical approaches are described to quantify these properties in both operating and greenfield mining environments. Case studies are presented where specific additional breakage properties and modelling features have been needed to generate a useful description of the fragmentation achieved.CITATION:Scott, A and Onederra, I, 2015. Characterising rock mass properties for fragmentation modelling, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 149–160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

CONTENTSIntroductionNorthern ExplorationDrive ConceptionGeneralDriving CrewDrive Cross Section and Track DetailsVentilation by Electrically Driven FanTemperatures and HumidityFan PerformanceRock Drill Carriage and Rock DrillsStandard Drilling RoundElectric Firing from Power MainsExplosives and DetonatorsCharging and FiringMechanical Loading and Electric HaulageOperating CycleStatisticalEquipmentAcknowledgementINTRODUCTION.The driving project described in :this paper is one of greater magnitude than usual for the Broken Hill field, and in the execution of the work a departure was made from long-established local practice by the introduction of mechanisation. The primary object of the drive is to provide sites for gaining information regarding the behaviour of the ore-bodies well beyond the limits of the present exposures.Due to thermal conditions, the major portion of the work was done on a six-hour shift basis, in contrast to the normal one of seven hours, with a five-day week.

Jan 1, 1946

With the launch of Immersive Technologies' next generation of Advanced Equipment Simulators for the mining industry, correlating and influencing safety, productivity and maintenance with operator competency improvements is now made even more effective. In early 2008, Immersive assembled a project team to investigate the potential linkages between operator competency and performance. Advanced Equipment Simulator Users with a range of sophistication were interviewed and consulted. The result was new and enhanced 'value realisation' programs to directly assist mine sites to deliver the expected return on investment (ROI) from simulators and operator competency development. In just over one year, 29 mine sites around the world have benefited from 34 completed programs. Case studies have been compiled to demonstrate the impact of the implementation of this approach, including at the following operations: Anglo Coal - Callide (Australia), Freeport McMoRAN - Grasburg (Indonesia), Equinox Minerals - Lumwana (Zambia), Peabody Energy - Cabllo (USA), and Xstrata - Lomas Bayas (Chile). Significant performance improvements have been achieved including: reductions of 47 per cent in gear shifting and 37 per cent in over speed errors, improvements of 68 per cent in park break errors and 12 per cent in spotting time, and increase of 54 per cent in passing emergency fire handling competency tests. This presentation draws on these case studies to clearly demonstrate the linkage between improved operator competency through the implementation of training programs tailored around Advanced Equipment Simulators and production performace measured by a range of standard metrics at mines around the world.

May 1, 2010

By B Muller

The disposal of tailings has become a greater issue due to the changing economics of mineral extraction. The processing of lower grade deposits and tougher environmental regulations has led to the selection process for tailings disposal options becoming more complicated. Current selection methods are too time consuming or too easily manipulated for inexperienced users to use successfully. This paper examines a different method for the initial selection of a tailings disposal system, using a numerical system that was introduced into the mining method selection field. The numerical method system was compiled by reviewing previous work done on the positive and negative aspects of the tailings disposal methods used by the coal and metallurgical mining industries. Assessing the common trends and design aspects of each of the methods was undertaken and a ranking was designed to explain how well suited the tailings disposal methods are to a situation. The tool successfully analysed sites using common data to indicate methods for disposal that would have provided minimal technical problems, low environmental risk and been practically possible. The tool also proved successful in identifying critical areas that would need further investigation. This new system was tested on some disaster case studies from around the world in order to show that it could have successfully selected a different method for tailings disposal that would have prevented the disaster.

Sep 26, 2011

By T Graham

Traditional iron ore wet beneficiation plants are large multilevel structures, often integrated into centralised processing plants. They are characterised by sizeable footprints, substantial water and power consumption, inflexible design and low scalability. Significant design changes that address these issues need to be made before relocatable modular plants become feasible. Firstly, large amounts of processing water are required in standard wet plants, so it is vital that water consumption is reduced to an absolute minimum. Secondly, the process of depositing tailings into tailings storage facilities (TSFs) is environmentally destructive, consumes significant power and requires lengthy approvals to be completed. Thirdly, modules need to be easily and quickly relocatable.The solution to reducing water usage and eliminating TSF requirements is accomplished by providing a tailings dewatering and dry-stacking capability into a separate module. This equipment needs to dewater tailings to a point (typically below 20 per cent moisture) where dry stacking becomes possible – design is mainly driven by material rheology and particle size distribution (PSD). In this respect, a flexible and scalable strategy is employed to dewatering modules, allowing a variety of components such as dewatering cyclone clusters, paste thickeners, fine mesh vibrating screens and filter presses to be used to achieve the necessary moisture level, enabling the final dry stacking to be accomplished by a simple telescopic stacking system. Plant relocatability also requires modules to comply with mass and dimensional constraints, as well as ‘plug and play’ ease-of-use features.For coarse particle upgrade, jigs provide a low-cost and effective solution, whereas fine and ultra-fine Fe units can be recovered using Wet High Intensity Magnetic Separation (WHIMS). Recently, sensor sorting – a dry process using X-ray fluorescence, X-ray transmission, laser or other sensors – has begun to make an impact in coarse particle separation, although capacities are still low. The overall objective of a plant is to provide an Fe upgrade of four to five per cent with a feed of up to 4 Mt/a and a recovery of approximately 50 per cent.CITATION:Graham, T, 2017. Relocatable modular beneficiation creates value from waste, in Proceedings Iron Ore 2017, pp 167–172 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By M C. Goode

The use of electrical or electronic safety systems to protect personnel, and the engineering tasks associated with the design, manufacture and maintenance of these systems are referred to using the term ‘functional safety’. In the past ten years, the use of such systems has transitioned from its traditional base, in oil and gas major hazard facilities, to being a part of most large mining and materials handling projects. In particular, functional safety is rapidly becoming a significant component of Australian iron ore projects, typically in the form of emergency stops, remote isolation, drive through interlock, robot cell entry or mobile machine anti-collision systems. While these types of systems have been in use in iron ore for a long time, functional safety standards (eg AS61508, AS62061, AS4024.1503) require more rigourous demonstration of the level of risk reduction provided by the systems.The early engineering project development phases require a number of key decisions to be made around functional safety implementation. The decisions made at this point in a project will go on to dictate the required types of risk assessment and analysis, equipment selection, sizing of substations, and training and maintenance requirements for owners. For project teams that are unfamiliar with functional safety, or inexperienced in its application, an incorrect decision or failure to understand the requirements of the chosen standard can lead to a failure to meet contract requirements, as well as major cost and schedule overruns.This paper examines the implications of functional safety on early engineering studies, focusing on the following questions: How does a designer or company determine what standard is best suited to their project? What key aspects of functional safety design need to be considered during project development? And finally, how can the impact of functional safety to the project be minimised?CITATION:Goode, M C, 2017. Functional safety impacts on study stages of major projects, in Proceedings Iron Ore 2017, pp 347–352 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By D R. Anstey

The mining of magnetite iron ore in Western Australia will generate large volumes of waste rock and tailings over many decades. The need to dispose of these materials will result in massive waste landforms that will require significant planning and management. The formation of comparable man-made landforms is relatively common, as exemplified through past practice in gold and iron ore (haematite) mining. Unfortunately, the performance of these landforms, with respect to long-term stability (erosion resistance), the release of low pH seepage water and aesthetic impact, has commonly been disappointing and environmental legacies have been created as a result. Lessons that have been learnt from past, large mining operations indicate that there is a need to rethink the methods of waste disposal and landform development applied to magnetite mining. The environmental compliance criteria applied to magnetite mines for the storage of tailings and waste typically include minimising dust generation (particularly as the tailings and mine waste may contain asbestiform minerals), control of silt, minimising visual intrusion and management of potentially acid forming materials. In addition, the climate of Western Australia and the paucity of both surface and groundwater in the vicinity of the magnetite mines frequently necessitate water consumption to be minimised. This paper discusses the potential to co-mingle magnetite mining waste streams in a variety of ways to concomitantly satisfy the environmental compliance criteria and the operational requirements of the mine. These methods include co-mingling of coarse tailings and waste through dry-stacking, deposition of tailings as a paste, co-disposing of all wastes to form an integrated landform and the co-mingling of all waste streams to produce PasteRockTM (a blend of tailings paste and crushed waste rock). The paper demonstrates how these techniques can be applied to the magnetite mining industry to provide better outcomes than might be achieved using more conventional techniques, currently employed in large-scale mining operations.

Jan 1, 2009

The implementation of robust, reliable and accurate sampling systems is the key to the successful management of any mineral processing plant. The representative sampling of a mineral processing plant is the only way to determine what is coming into the plant, what is going out as fi nal product and what is going to tails. In plants with high gravity gold components, where high recovery effort gravity circuits are installed, the use of a gravity recoverable gold (GRG) sampling system can assist in the online monitoring of the performance of the circuit. The typical installation location would be in CIP or fl otation feed (ie cyclone overfl ow), downstream of the gravity circuit. A GRG sampling system generally consists of the following equipment: true proportional, continuous drive, linear cross cut sampler, secondary vezin sampler operated on a timer, a batch centrifugal concentrator, and sample dewatering module. The operating philosophy of the GRG sampling system is that the primary sampler operates on a continuous basis, generating a constant stream of truly representative sample. Consep's H&S drive system is unique in its ability to be able to operate in a continuous mode, therefore enabling a continuous stream of representative sample to be generated. The primary sample stream reports to the secondary sampler. The secondary sampler operates on an intermittent basis (nominally ten minute interval), resulting in a relatively small sample volume per shift. Normally the sample volume would be ten to 15 L per shift. The secondary sample rejects stream reports back to the batch centrifugal concentrator. The sample generated from the secondary sampler can be dewatered using a Consep H&S dewatering module. This device produces a final sample that consists of separate filter cake and filtrate. These are suitable for taking directly to the laboratory. The continuous stream of truly representative secondary sampler rejects is passed through an appropriately sized Knelson Concentrator, typically a KCMD7, KCCD10 or KCCD12 sized unit. This unit recovers any available GRG from the stream. The Knelson Concentrator is also purged of its gravity concentrate at the end of the shift. This sample, which is nominally around 1 - 2.5 kg of concentrate, is also taken to the laboratory. At the end of the shift the client will have a measure of the gravity recoverable gold content of the target slurry stream, as well as a true representative sample of the complete stream. Through the addition of a Knelson Concentrator to an otherwise typical sample station, it is possible to generate a true measure of the performance of your gravity circuit. This will take the guess work out of the daily variation in gravity circuit gold recovery, as the site knows whether the changes are due to gravity circuit equipment performance, or due to the natural variation of ore GRG contents. Maintenance planning can also be designed around the system, as the site will have a composite sample to measure the performance of the circuit, therefore indicating where performance has dropped and maintenance is needed. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Aug 1, 2010

By P J. Sack, L V Danyushevsky

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Regional-scale exploration for sediment-hosted gold deposits is hampered by the challenge of evaluating the fertility of ancient sedimentary sequences that host these deposits. Recent developments in laser ablation inductively coupled plasma mass spectrometry allow for the evaluation of the gold fertility of sedimentary sequences using chemistry of early-formed sedimentary pyrite. We present a case study from the Selwyn basin area of Yukon, Canada, where significant sediment-hosted gold exploration has been ongoing for the last five years. Data from sedimentary pyrite in some Neoproterozoic shales are anomalous in Au and As compared to a global data set of unmineralised sedimentary pyrite. If at least some of the gold and associated trace elements in sediment-hosted gold deposits are derived from recrystallisation of early sedimentary pyrite, it follows that strata containing anomalous sedimentary pyrite should be more prospective. Based on this premise, our data clearly show that Yusezyu Formation Neoproterozoic shales in the Selwyn basin area of Yukon are a fertile source rock for sediment-hosted gold deposits, while pyrite from Nadaleen formation shales are strongly anomalous in Hg and Tl, but not Au. We suggest that the area warrants continued exploration for sediment-hosted gold.CITATION:Sack, P J, Gregory, D D, Large, R R and Danyushevsky, L V, 2015. Using sedimentary pyrite chemistry to inform regional exploration for sediment-hosted gold deposits – a gold fertility case study from the Selwyn basin area, Yukon , in Proceedings PACRIM 2015 Congress, pp 69–76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By B Hou

The Eucla Basin in southern Australia is emerging as an important global source of zircon from heavy mineral sands. Understanding the geological evolution of the basin and movement of heavy minerals down peripheral paleovalleys and along paleocoastlines is essential to effectively refine exploration strategies for heavy minerals in the basin. Integration of geoscientific datasets in a Geographic Information System (GIS) environment has proved to be effective in reconstructing depositional environments along the Cenozoic basin margin and in tracing the buried paleorivers that once drained broad areas of the Archean-Paleoproterozoic Yilgarn and Gawler cratons, the dominantly Mesoproterozoic Musgrave and Albany-Fraser Provinces, and the Neoproterozoic-Early Paleozoic Officer Basin. Sea level highstands during the late Middle Eocene (39 - 36 Ma) are associated with formation of the Ooldea coastal barrier complex and the zircon-rich heavy mineral deposits at Jacinth, Ambrosia and Tripitaka. More extensive transgression during the Late Eocene (36 - 34 Ma) built the complex Barton shorelines that host the Cyclone deposit and the extensive ilmenite-dominated occurrences of the Barton West prospect. Multi-generation reworking of the source sands is indicated by the high proportion of deposits that are zircon-rich relative to titanium minerals. The age distribution of zircon grains in heavy mineral concentrates from the Ooldea and Barton barrier systems points to the Musgrave Province as the predominant ultimate zircon source. Paleorivers discharging along the northern basin margin presumably carried a sediment load that was then redistributed by easterly longshore drift to build the extensive coastal sand deposits along the northern and eastern basin margin. The south-eastern extension of these deposits was reworked during Miocene-Pliocene (15 - 2 Ma) times into a series of regressive strandlines that show angular discordance with the Eocene coastlines. This discordance is consistent with evidence for long-wavelength tilting of the Australian continent from Middle Miocene times, as the continent drifted toward a dynamic topographic low induced by convective mantle processes associated with the South East Asia subduction systems. The Dromedary and Gulliver’s deposits probably formed at this time. Ongoing research is focused on the geological features of the basin that influence heavy mineral transport, concentration and preservation, and the processes leading to deposits with high zircon content.

Oct 5, 2011

By N Swiegelaar

Loubert Witbank is a defunct coal mine situated near Ermelo in South Africa. Mining ceased in 1992, and within a short period acidic decant occurred, with a significant impact on the regional catchment. The problem was studied during 1996/1997, and the site remediated in 2001/2002 by the Department of Water Affairs and Forestry. Remediation involved primarily submerging of carbonaceous material, backfilling of voids, and capping of the site. Acidic water with high iron levels was also neutralised and discharged. The project was used to assess the cost benefit of different options to the downstream users, from which target expenditure was derived for the various improvements. The cost benefit analysis for neutralisation provided a basis for the investigation of low-cost neutralisation options that are robust enough to be applied in a remote environment.

Jan 1, 2003

Since the 1950's drilling has been rapidly mechanised. First from hand held drills with air legs to pneumatic jumbos, then to more effective hydraulic jumbos. Development of underground drilling equipment naturally could not have stopped here. Hydraulic drilling saw an improvement in drilling capacity and efficiency after the introduction of second generation drifters in the early 1980's. Also in the early 1980's a few equipment suppliers started to study how to improve the efficiency in operating the rigs. The first computerised rigs for tunnelling were delivered to work sites in mid 1980's. At the same time a few computerised longhole drills started drilling in mines.

Jan 1, 1988

By K Niyomjinda, B Etschmann

Chatree Gold Mine is currently the only modern day gold mine operating in Thailand, and is situated approximately equidistant from Chiang Mai in the north and Bangkok in the south. Environmental guidelines set by the Thai authorities require Chatree Gold Mine to achieve a Total Cyanide level of 20 ppm or less in the process plant discharge slurry stream prior to release into the tailings storage facility. This paper describes both the initial difficulties faced in achieving compliance on this limit utilising the conventional INCO SO2/Air cyanide destruction system and the subsequent process improvements initiated to both the leaching process and the standard INCO process to achieve the current compliance levels of approximately 99/100 shifts. Improvements were focussed on the dual aspects of reducing the formation of WAD cyanide and ferrocyanide species in the leaching circuit coupled with process changes to improve removal of the ferrocyanide species from solution during the cyanide reduction stage.

Jan 1, 2004

By Watson D. F

P S B Stewart has rightly pointed to a possible obscurity in our paper on drilling patterns, viz. in comparing the improvement of a triangular drilling pattern over a square one, we used percentage improvements without always making clear their base. We hope, however, that other readers, like Stewart, have been able to understand the particular meaning from the context.Although different methods of estimation of an ore deposit will have different local bias (Philip and Watson, 1985), the critical relationship affecting the reliability of estimation of an unsampled location is the scale of local variation of the variable being estimated in comparison with the density and isotropy of sampling. This relationship overrides all other considerations.

Jan 1, 1985

Although the title of this paper permits a very broad scope for discussion, I propose to deal mainly with those aspects of design part- icularly related to rook filling, the'theme of this conference. The unique suitability of belt conveyors for the continuous economical delivery of materials into or out of underground workings, is well established and needs no elaboration. The facility with which conveyor units, comprised of modern modular components, can be adjusted to lengthen or shorten, their ability to be readily repositioned to suit the develop- ment of a work pattern and their virtues as low noise, reliable transport media, are already accepted by all who are involved with the mining industry.

Jan 1, 1973

At the LKAB, Iron Ore Mine, Kiruna, Sweden a preliminary investigation into the reliability characteristics of a fleet of load-haul-dump machines has shown that the hydraulic system is one of the most critical parts. Therefore, hydraulic system was selected for study and analysis through condition monitoring devices so that failure can be controlled or at least the failure consequences can be minimized.The hydraulic system has two different problems; one is that the contamination level is too high and the other is high temperature during operation. At high temperature, seals and tubes are a problem, because they stiffen due to carbonization, which leads to increasing leakage. The pumps and restrictions were responsible for the main temperature increase.

Jan 1, 1991

The control of industrial grinding circuits in Australian concentrators has been practised for many years in one form or another. Some have established simple feedback loops in areas such as fine ore bin feeders (tonnage control), mill pump sump levels (flow control) and water additions (density control). There are also some sophisticated systems which infer circuit product size using complex measurements of mass flaws and water additions in the circuit and attempts are made to control those flaws to produce a constant circuit product size. The inferred size method in Australian concentrators has become firmly entrenched in the last ten years and control techniques involving the use of direct size measurements with reliable on-stream sizers have been Ignored.

Jan 1, 1983

Based upon specialised experience of rope mechanics spanning over 20 years, this paper reviews the processes of degradation and fatigue that are relevant to hoisting ropes in mines. The review is brought up to date with an account of the most recent work in this field, which identifies a torsional fatigue process and quantifies the impact of degradation upon the residual service life. A proper understanding of these processes is important in determining how different parameters of hoist design and operation interact to determine rope life. This knowledge is also important in informing decisions relating to rope discard based upon observed condition, as well is identifying the critical features that must be quantified reliably during inspection.

Jan 1, 2005

By Baafi EY, Chatterjee PK

The quality of mine planning decisions ultimately depends on reliable estimates of the characteristics of the orebody. The quant- ifiable factors such as grades or thickness can be estimated from field data gathered from outcrops or exploratory drillholes. Since outcrop data is necessarily limited to the periphery of a deposit, extensive drilling generally is required. This paper outlines a method for selecting the number and location of additional exploratory boreholes using an iterative procedure based on a mathematical optimization concept called fixed point theory. The method is illustrated through its application to an exploratory drilling program for a coal mine where optimized locations gave a lower estimate of regional and block variances than a manual Choice.

Jan 1, 1986

An integrated mining equipment development organisation is typified by Deutsche Montsn Technologic of Essen, Germany. working on improvements in reliability, production and control in coal mines. Examples of recent mining advances are in mechanised roadheading, in different approaches to cutting technology, and in low height roof bolting.On the longwall face the mechanics of cutting are related to supplied energy as well as to dust make. In conveying both armoured face conveyors and conveyor belts are monitored. Roof support is not neglected and the continuous pumping of stowage slurries provides further options for longwall support. Surveying developments, particularly the gyro-theodolite, directional drilling. and shaft vehicle monitoring provide further examples of advances in control in coal mining activities.

Jan 1, 1991